Open Paleo

Rhoetosaurus

Longman, 1926 REET-o-SAWR-us

Named for Rhoetus, a giant (Titan) in Greek mythology, combined with Greek 'sauros' meaning 'lizard'; meaning 'Rhoetus lizard.'

165.3–154.8 million years ago Callovian–Oxfordian, Middle Jurassic–Late Jurassic
Middle Jurassic and Late Jurassic stages

Rhoetosaurus is a genus of sauropod dinosaur from the Walloon Coal Measures of what is now eastern Australia. Rhoetosaurus is estimated to have been about 15 meters (49 ft) long, weighing about 9 tonnes (8.9 long tons; 9.9 short tons). Subsequent authors have sometimes misspelled the name: "Rhaetosaurus" (de Lapparent and Laverat, 1955); "Rheteosaurus" (Yadagiri, Prasad and Satsangi, 1979).

Under dispute

Rhoetosaurus is recovered as a non-eusauropodan gravisaurian, possibly the most derived of all known non-eusauropods (Nair and Salisbury, 2012). Some earlier treatments allied it with basal eusauropods or the historical Cetiosauridae.

Diagnosis

  1. Tibia with multiple distal crests and sulci medially
  2. Concentric proximal fossa on the medial surface of the tibia
  3. Mid-lateral surface of the fibula osteologically featureless, lacking a tubercle or scar
  4. Proximal articular surfaces of the metatarsals elliptical and narrow dorsoplantarly, developed to a lesser extent in Shunosaurus
  5. Prominent crest and apical process on the medial side of the cranial face of metatarsal II, with lesser ridges also present in diplodocids
  6. Second phalanx of digit II triangular in dorsal outline
  7. Lateral crest on the first phalanx of digit IV
  8. Accessory fossa or groove on the medial face of the pedal unguals

Species

Rhoetosaurus brownei Longman, 1926

Type species

Named for Arthur Browne, the station manager at Durham Downs who forwarded the first fossil fragments to paleontologist Heber Longman and thereby enabled the discovery.

Syntype
QM F1659 , Queensland Museum, Centre for Biodiversity
Material
22 caudal vertebrae (some fractured), fragments of femur, tibia, fibula, and pelvic elements; over 100 specimens total
Notes
The syntype series and the referred material share the single registration number QM F1659, so the number denotes the hypodigm rather than the type series alone.
Horizon
Walloon Coal Measures Group, Callovian–Oxfordian, Middle Jurassic–Late Jurassic , 165.3–154.8 million years ago
Locality
Eurombah Creek, Taloona Station, Queensland, Australia The type locality lay on Durham Downs Station when the holotype was collected and now lies on Taloona Station, the property having since been subdivided.

References

  1. Longman, H. A. (1926). A giant dinosaur from Durham Downs, Queensland. Memoirs of the Queensland Museum 8(3): 183-194. longman1926a
  2. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Sauropods. Princeton University Press.

    Source of the hip height estimate.

    jones2026b
  3. Todd, C. N.; Roberts, E. M.; Knutsen, E. M.; Rozefelds, A. C.; Huang, H. Q.; Spandler, C. (2019). Refined age and geological context of two of Australia's most important Jurassic vertebrate taxa (Rhoetosaurus brownei and Siderops kehli), Queensland. Gondwana Research 76: 19-25. doi:10.1016/j.gr.2019.05.008

    Dates the holotype's matrix to a maximum depositional age of 162.6 ± 1.1 Ma, late Callovian to earliest Oxfordian on the current chart.

    todd2019a
  4. Nair, J. P.; Salisbury, S. W. (2012). New anatomical information on Rhoetosaurus brownei Longman, 1926, a gravisaurian sauropodomorph dinosaur from the Middle Jurassic of Queensland, Australia. Journal of Vertebrate Paleontology 32(2): 369-394. doi:10.1080/02724634.2012.622324

    Redescribed Rhoetosaurus and recovered it as a non-eusauropodan gravisaurian

    nair2012a
  5. Jannel, A.; Nair, J. P.; Panagiotopoulou, O.; Romilio, A.; Salisbury, S. W. (2019). "Keep your feet on the ground": Simulated range of motion and hind foot posture of the Middle Jurassic sauropod Rhoetosaurus brownei and its implications for sauropod biology. Journal of Morphology 280(6): 849-878. Wiley. doi:10.1002/jmor.20989

    Biomechanical study; its illustrative cladogram (reanalyzing Carballido and colleagues 2017) shows Rhoetosaurus outside Neosauropoda but makes no independent placement claim.

    jannel2019a
  6. Lapparent, A. F. de; Lavocat, R. (1955). Dinosauriens. Traité de Paléontologie, Tome V 785-962. Masson.

    Rendered the name as "Rhaetosaurus" in a review of dinosaurs.

    lapparent1955a
  7. Yadagiri, P.; Prasad, K. N.; Satsangi, P. P. (1979). The sauropod dinosaur from the Kota Formation of Pranhita-Godavari Valley, India. Fourth International Gondwana Symposium, Papers 1: 199-203. Hindustan Publishing Corporation.

    Rendered the name as "Rheteosaurus" in a report on the Kota sauropod.

    yadagiri1979a